Buying a home is the largest purchase most people ever make. Buyers work intensely to identify their needs and wants, assess the individual benefits of various choices and evaluate the long-term financial return to ensure they make a quality decision. Once living in that new home, kitchen remodels and reroofing can be the largest expenses faced by homeowners.

In addition to increasing curb appeal, modern tile roofing systems and accessories offer an opportunity to improve the energy efficiency ofa home.

We all have firsthand, daily experience with our kitchen. We know what we like and what we don’t. Advertisements showing features and benefits of new appliances, more spacious cabinets and better lighting are appealing. Learning and planning for a new kitchen is fun and exciting. We know we will use it every day and we can show it off to our friends. We choose to do a kitchen remodel.

Reroofing is different. The process usually starts with a surprise—a roof leak a repairman fails to resolve. Then a second attempt, maybe a third, followed by an explanation that the system has reached the end of its useful and serviceable life. Reroofing becomes necessary to preserve the integrity of the home. It’s not fun and it’s not by choice. Compared to new stainless-steel appliances, soft-close drawers and a built-in wine cooler, it’s not exciting.

With little understanding of modern roofing, the first (and often only) question asked is, “How much is it going to cost?” If lowest initial cost was the only criteria for a roof, we would all have blue tarps overhead.

The true cost of roofing is defined by the life-cycle cost, which includes consideration of the initial cost, life expectancy, potential energy savings and potential insurance discounts.

A quality tile roof installation will set a home apart from neighboring homes now and will be a great investment to help the home garner the best sale price later. This is where a knowledgeable contractor can help a homeowner identify his or her needs and wants, assess the benefits of various choices and calculate the value of the given system.

1. IDENTIFY THE HOMEOWNER’S NEEDS AND WANTS

Residential roofing is a functional part of the building envelope. Its primary purpose is to protect the home and its contents from the elements. Residential roofing is also a largely visible part of a home’s curb appeal. A tile roof will increase the curb appeal of a house when compared to similar homes with less substantial roofing materials.

Concrete and clay roof tiles’ resistance to weathering, hail, high winds and UV means that look of quality will be consistent from the day the roof is installed until the day it helps the homeowner get the best return on his/her original investment by enhancing the home’s curb appeal when the house is sold. Without the excitement of center islands and granite counter- tops, the homeowner needs help to be informed about options and benefits a tile roof can provide.

2. ASSESS THE BENEFITS OF VARIOUS CHOICES

In addition to increasing curb appeal, modern tile roofing systems and accessories offer an opportunity to improve the energy efficiency of a home. The inherent insulation properties created by tile’s high thermal mass can be enhanced with above-sheathing ventilation, or ASV. These raised batten systems can “… offer a significant 50 percent reduction in the heat penetrating the conditioned space compared to direct nailed roof systems that are in direct contact with the roof deck,” says Dr. William Miller, Ph.D., P.E., Oak Ridge National Laboratory, Oak Ridge, Tenn.

The energy savings of ASV is recognized by the California Energy Commission, Sacramento, and included in the Title 24 Energy Code revisions for reroofing and alterations. (Learn more about ASV in “Details”, March/April 2015 issue, page 79.)

Power Shield Inc. has introduced roof tiles that have solar cells embedded into them.

Power Shield Inc. has introduced roof tiles that have solar cells embedded into them. The tiles are designed to cover the whole roof. The Power Shield roof system features a cool roof coating, above-deck ventilation, and is made from recycled and non-combustible, lightweight steel. Energy is produced through the 16 watts of power per solar tile. Building-envelope thermal performance is improved through:

Cool roof coatings on tile keep it cool and improve energy production. The cool roof coating has high emissivity on the sun side to allow heat to be radiated out and low emissivity underneath, making the tiles a radiant barrier.

The efficient above-sheathing ventilation on the tile system provides a chimney effect as warm air flows between the tiles and the roof deck and out from the building. In winter, the air gap between the tiles and roof deck are insulating, reducing the heat transfer out of the attic.

We know proper ventilation of the attic space is an important part of construction. But what is “above-sheathing ventilation”?

Most roofing materials lay directly on the sheathing. Heat from solar radiation and interior heat loss from the conditioned space are easily transferred through the deck and roof system. This can increase energy costs and cause ice damming. The build-up of heat and extreme temperatures wings can also reduce the life of underlayment and other system components.

Tile roofs have an air space between installed roof tiles and the roof sheathing. This space reduces heat transfer and allows heat buildup to dissipate from the sheathing and roofing materials. This above-sheathing ventilation, or ASV, inherent to tile roof installations can be enhanced using counter battens, shims or manufactured systems to raise the horizontal battens above the roof deck. The system design will vary with the environmental challenge and goals. Specific examples are described below.

The Elevated Batten System by Boral Roofing uses treated 1 by 2s with high-grade plastic pads, a vented eave riser flashing and vented weather blocking at the ridge. With these components in place, heat transfer is minimized and heat buildup is dissipated, which reduces energy costs.

Energy Conservation in Hot Climates

In hot and dry climates, the natural ASV and thermal mass of the tile provide a layer of insulation when exterior daytime temperatures are greater than the conditioned space in the home. Vertical counter battens or shims that raise the horizontal battens increase this space and the corresponding benefit. The addition of vented eave riser flashing and ridge ventilation completes an energy-saving ASV system. The system shown below is the Elevated Batten System made by Boral Roofing, which uses treated 1 by 2s with high-grade plastic pads, a vented eave riser flashing and vented weather blocking at the ridge. With these components in place, heat transfer is minimized and heat buildup is dissipated, which reduces energy costs. The upgraded ASV reduces temperature extremes that shorten the life of the underlayment and other roofing components. These benefits are achieved with no mechanical or moving parts.

Cool and Humid Climates

The same installation can provide a different benefit in cool and humid regions. The Tile Roofing Institute and Western States Roofing Contractors Association’s Concrete and Clay Tile Installation Manual for Moderate Climate Regions says that in areas designated “Cool/Humid” zones, “Batten systems that provide drainage/air-flow (shims, counter battens or other approved systems) are required.” The area designated “Cool/Humid” in the current manual runs from approximately Eureka, Calif., to the Pacific Northwest, west of the Cascade Mountains. In this climate, moisture-laden air can migrate under the tile and condense in the space between the tile and roof deck. The underlayment is there to protect the sheathing but if the battens are raised above the deck, condensation will be reduced. Raised battens also allow moisture under the tile to escape to the eave. When roof tiles are fastened to a raised batten, underlayment penetrations are minimized.

Cold and Snowy Regions

Ice dams are one of the most damaging phenomena roofing contractors face. Snow movement on roof surfaces can cause damage to people and property. The goal in cold and snowy environments is to prevent ice dams by enhancing the ASV under the tile roof. Typically, a more substantial air space is created using larger vertical battens. A well-designed “cold roof” system that includes proper snow retention is the solution.

The TRI/WSRCA Concrete and Clay Tile Installation Manual for Moderate Climate Regions refers installers to the TRI/WSRCA Concrete and Clay Roof Tile Design Criteria Installation Manual for Cold and Snow. Regions “in locations where the January mean temperature is 25 deg. F or less or where ice damming often occurs”.

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July/August 2017 issue

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About Roofing

Roofing is a national publication that unravels, investigates and analyzes how to properly design, install and maintain a roof system. Through the voices of professionals in the field, Roofing’s editorial provides a unique perspective.